考虑压剪耦合特性的岩土材料广义非线性屈服准则

 针对岩土材料的压剪耦合特性，将原广义非线性强度理论(GNST)扩展为可合理考虑岩土材料屈服与破坏特性的广义非线性屈服准则。在偏平面上，屈服准则表达式采用SMP准则与广义Mises准则的插值表达式；在子午面上，屈服准则表达式采用可考虑压剪耦合特性的封闭曲线表达式。由于在过渡空间中建立相应的屈服准则表达式，因此与已有的Matsuoka-Nakai准则与Lade-Duncan准则的插值准则(MNLD准则)相比，新准则描述屈服时采用非线性强度曲线，同时能够更合理地考虑静水压力对于偏平面以及子午面上屈服特性的影响，模型参数均具有物理意义，且通过常规试验可以确定。通过不同岩土材料的破坏以及屈服特性的试验预测对比，验证了新准则在描述岩土材料压剪耦合特性方面的合理性。

A NEW GENERALIZED NONLINEAR YIELD CRITERION FOR GEOMATERIALS CONSIDERING COUPLING BEHAVIOR OF SHEARING AND COMPRESSION

A new generalized nonlinear yield criterion(GNYC) is proposed to describe the yield and failure behaviors of geomaterials，including the coupling behavior of shearing and compression，through extending the generalized nonlinear strength theory(GNST). The interpolation function between SMP criterion and generalized von Mises criterion is adopted as the yield function of the new criterion on deviatoric plane；while the closed curve function considering coupling behavior of shearing and compression is adopted as the yield function on meridian plane. As the yield function is established in the transitional stress space，the nonlinear power function is adopted as the failure curve in new yield criterion，which can be described using the proposed criterion compared to the MNLD criterion(interpolation criterion between Matsuoka-Nakai criterion and Lade-Duncan criterion). The influence of the variation of hydrostatic stress on yield behavior on deviatoric and meridian planes can also be described more reasonably by the new criterion. There are physical meanings for all parameters in the new criterion and the values of parameters can all be determined by conventional tests. The validity of the new criterion is confirmed by data from yield and failure tests of different geomaterials.